In recognition of the fact that surfaces being shaved are not perfectly planar, a razor head comprising a cap, two blades separated by a spacer, and a guard bar have been designed such that the entire razor head flexes as a unit during shaving. In order to maximize the flexibility of the blade seat, one design includes a guard bar formed of a plurality of discrete segments. These segments are independently supported by the blade seat. Adjacent segments of the guard bar are thus separated by spaces. This segmented guard bar design has proven very successful in providing overall flexibility to the razor head without noticeable distortions to the blade geometry during shaving.
The consistent achievement of a close, comfortable shave depends upon careful control of the blade geometry. To this end, the present invention is directed to further improvements in razor heads utilizing segmented guard bars.
Those skilled in the art appreciate that a guard bar, which is designed to be the first element of a safety razor to contact a given area during a shaving stroke, affects the manner in which the skin approaches the edge of the seat blade. During a shaving stroke, skin typically flows over a guard bar and into the space between the guard bar and seat blade some distance below a tangent drawn from the top of the guard bar to the blade edge. The degree to which skin may flow below such a tangent line depends upon the seat blade span, i.e. the distance between the guard bar and seat blade edge.
Though the spaces between segments of a segmented guard bar have been designed to minimize the amount of skin which is not actually contacted by the guard bar segments during a shaving stroke, variations in the skin flow may still result. The skin flowing through the spaces between the segments may contact the seat blade edge at a different angle than the skin flowing over the guard bar segments. Additionally, when a flexible razor head having a segmented guard bar flexes in response to forces encountered during shaving, the space between at least some of the segments increases. This space increase further increases the possibility of a non-uniform skin flow immediately forward of the seat blade. A non-uniform skin flow may adversely affect the comfort of the shave.
It would therefore be desirable to provide greater skin flow control to a segmented guard bar to further minimize and preferably eliminate potential variations in skin flow over a segmented guard bar and thereby provide better control of the blade geometry during shaving.